fix purchase due date

internal/modules/purchases/dto/purchase.dto.go

@@ -14,11 +14,12 @@ import (
 )
 
 type PurchaseRelationDTO struct {
-	Id       uint       `json:"id"`
-	PrNumber string     `json:"pr_number"`
-	PoNumber *string    `json:"po_number"`
-	PoDate   *time.Time `json:"po_date"`
-	Notes    *string    `json:"notes"`
+	Id         uint       `json:"id"`
+	PrNumber   string     `json:"pr_number"`
+	PoNumber   *string    `json:"po_number"`
+	PoDate     *time.Time `json:"po_date"`
+	CreditTerm int        `json:"credit_term"`
+	Notes      *string    `json:"notes"`
 }
 
 type PurchaseListDTO struct {
@@ -64,11 +65,12 @@ type PurchaseItemDTO struct {
 
 func ToPurchaseRelationDTO(p *entity.Purchase) PurchaseRelationDTO {
 	return PurchaseRelationDTO{
-		Id:       p.Id,
-		PrNumber: p.PrNumber,
-		PoNumber: p.PoNumber,
-		PoDate:   p.PoDate,
-		Notes:    p.Notes,
+		Id:         p.Id,
+		PrNumber:   p.PrNumber,
+		PoNumber:   p.PoNumber,
+		PoDate:     p.PoDate,
+		CreditTerm: p.CreditTerm,
+		Notes:      p.Notes,
 	}
 }
 

internal/modules/purchases/services/purchase.service.go

@@ -309,21 +309,17 @@ func (s *purchaseService) CreateOne(c *fiber.Ctx, req *validation.CreatePurchase
 		indexMap[key] = len(aggregated) - 1
 	}
 
-	// var dueDate *time.Time
-	// if req.DueDate != nil && strings.TrimSpace(*req.DueDate) != "" {
-	// 	parsed, err := utils.ParseDateString(strings.TrimSpace(*req.DueDate))
-	// 	if err != nil {
-	// 		return nil, utils.BadRequest("Invalid due_date, expected YYYY-MM-DD")
-	// 	}
-	// 	parsed = parsed.UTC()
-	// 	dueDate = &parsed
-	// }
+	var dueDate *time.Time
+	now := time.Now().UTC()
+	d := now.AddDate(0, 0, req.CreditTerm)
+	dueDate = &d
 
 	purchase := &entity.Purchase{
 		SupplierId: uint(req.SupplierID),
-		// DueDate:    dueDate,
-		Notes:     req.Notes,
-		CreatedBy: uint(actorID),
+		CreditTerm: req.CreditTerm,
+		DueDate:    dueDate,
+		Notes:      req.Notes,
+		CreatedBy:  uint(actorID),
 	}
 
 	items := make([]*entity.PurchaseItem, 0, len(aggregated))
@@ -683,6 +679,7 @@ func (s *purchaseService) ReceiveProducts(c *fiber.Ctx, id uint, req *validation
 
 	visitedItems := make(map[uint]struct{}, len(req.Items))
 	prepared := make([]preparedReceiving, 0, len(req.Items))
+	var earliestReceived *time.Time
 	for _, payload := range req.Items {
 		item, exists := itemMap[payload.PurchaseItemID]
 		if !exists {
@@ -694,6 +691,10 @@ func (s *purchaseService) ReceiveProducts(c *fiber.Ctx, id uint, req *validation
 			return nil, utils.BadRequest(fmt.Sprintf("Invalid received_date for item %d", payload.PurchaseItemID))
 		}
 		receivedDate = receivedDate.UTC()
+		if earliestReceived == nil || receivedDate.Before(*earliestReceived) {
+			copy := receivedDate
+			earliestReceived = &copy
+		}
 
 		warehouseID := uint(item.WarehouseId)
 		overrideWarehouse := false
@@ -869,6 +870,16 @@ func (s *purchaseService) ReceiveProducts(c *fiber.Ctx, id uint, req *validation
 			return err
 		}
 
+		// Update due_date based on earliest received date when receiving approved.
+		if earliestReceived != nil {
+			due := earliestReceived.AddDate(0, 0, purchase.CreditTerm)
+			if err := tx.Model(&entity.Purchase{}).
+				Where("id = ?", purchase.Id).
+				Update("due_date", due).Error; err != nil {
+				return err
+			}
+		}
+
 		if s.FifoSvc != nil {
 			for _, adj := range fifoAdds {
 				if adj.pwID == 0 || adj.qty <= 0 {

internal/modules/purchases/validations/purchase.validation.go

@@ -8,6 +8,7 @@ type PurchaseItemPayload struct {
 
 type CreatePurchaseRequest struct {
 	SupplierID uint                  `json:"supplier_id" validate:"required,gt=0"`
+	CreditTerm int                   `json:"credit_term" validate:"required,number,gte=0"`
 	DueDate    *string               `json:"due_date,omitempty" validate:"omitempty,datetime=2006-01-02"`
 	Notes      *string               `json:"notes" validate:"omitempty,max=500"`
 	Items      []PurchaseItemPayload `json:"items" validate:"required,min=1,dive"`